System and method for local packet transport services within distributed routers

Abstract

A system and method for routing packets within a router having a plurality of loosely-coupled route processors, including a first route processor, and a line card operably coupled to the plurality of distributed-route-processors. Each route processor includes an internal forwarding information base (IFIB). Each IFIB includes information that is used to route packets addressed to elements within the router.

1. A computerized method for handling a packet fragment in a router having a plurality of router elements, wherein the router elements include a plurality of route processors, wherein the plurality of route processors includes a first route processor, the method comprising:
 building an Internal Forwarding Information Base (IFIB), wherein the IFIB maps one or more flows to router elements; 
 receiving a packet fragment; 
 forwarding the packet fragment to the first route processor; 
 processing the packet fragment with other packet fragments in order to assemble a reassembled packet; 
 accessing information from the IFIB for forwarding information associated with the reassembled packet; and 
 forwarding the reassembled packet to one of the plurality of route processors as a function of the IFIB associated with the reassembled packet, 
 wherein each router element includes a Pre-IFIB, wherein a subset of entries in the IFIB are stored in each Pre-IFIB, and wherein forwarding the reassembled packet to one of the plurality of route processors as a function of the IFIB includes accessing the Pre-IFIB. 
 
     
     
       2. The method of handling a packet fragment according to  claim 1 , wherein each route processor includes a Pre-IFIB, wherein a subset of entries in the IFIB are stored in each Pre-IFIB, and wherein forwarding the reassembled packet to one of the plurality of route processors as a function of an internal forwarding information base (IFIB) includes accessing the Pre-IFIB. 
     
     
       3. A computer-readable medium which, when installed on one or more processors, executes the method of  claim 1 . 
     
     
       4. The computerized method of  claim 1 , wherein forwarding the reassembled packet to one of the plurality of route processors includes forwarding the reassembled packet to a route processor if the reassembled packet includes information that matches an entry in the internal forwarding information base (IFIB). 
     
     
       5. The computerized method of  claim 1 , wherein accessing information from the Internal Forwarding Information Base (IFIB) includes requesting a dynamic policy for the reassembled packet if the packet does not match an entry in the internal forwarding information base (IFIB). 
     
     
       6. The computerized method of  claim 5 , wherein the method further comprises:
 rejecting a connection request if a dynamic policy is not available for the reassembled packet; and 
 generating an error response upon rejecting the connection request. 
 
     
     
       7. A computerized method for handling a packet fragment in a router having a plurality of route processors, including a route processor, the method comprising:
 receiving a plurality of packets; 
 detecting packet fragments among the plurality of packets; 
 routing the packet fragments to one of the plurality of route processors as a function of a packet fragment routing policy; 
 assembling the packet fragments into a reassembled packet; and 
 routing the reassembled packet to another one of the plurality of route processors as a function of an internal forwarding information base (IFIB) that maps one or more flows to the plurality of route processors, 
 wherein one of the plurality of route processors includes a Pre-IFIB, wherein a subset of entries in the IFIB are stored in the Pre-IFIB, and wherein routing the reassembled packet to the another one of the plurality of route processors as a function of the IFIB includes accessing the Pre-IFIB. 
 
     
     
       8. The method of handling a packet fragment according to  claim 7 , wherein routing the packet fragments to one of the plurality of route processors as a function of a packet fragment routing policy includes generating an address as a hash of source and destination addresses associated with the packet fragment. 
     
     
       9. A computer-readable medium which, when installed on one or more processors, executes the method of  claim 7 . 
     
     
       10. The computerized method of  claim 7 , wherein routing the reassembled packet to the another one of the plurality of route processors as a function of the IFIB includes generating an error response if there is no entry in the IFIB corresponding to the reassembled packet. 
     
     
       11. The computerized method of  claim 10 , wherein generating an error response includes:
 rejecting a connection request if a dynamic policy is not available for the reassembled packet; and 
 generating an error message upon rejecting the connection request. 
 
     
     
       12. A router, comprising
 a plurality of router elements, wherein the router elements include a plurality of route processors, wherein the plurality of route processors includes a first route processor; 
 means for maintaining an Internal Forwarding Information Base (IFIB), wherein the IFIB maps one or more flows to router elements; 
 means for receiving a packet fragment and for forwarding the packet fragment to the first route processor; 
 means for processing the packet fragment with other packet fragments in order to assemble a reassembled packet; 
 means for accessing information from the Internal Forwarding Information Base (IFIB) for forwarding information associated with the reassembled packet; and 
 means for forwarding the reassembled packet to one of the plurality of route processors as a function of the IFIB associated with the reassembled packet, 
 wherein each router element includes a Pre-IFIB, wherein a subset of entries in the IFIB are stored in each Pre-IFIB, and wherein the means for forwarding the reassembled packet to one of the plurality of route processors as a function of the IFIB includes means for accessing the Pre-IFIB. 
 
     
     
       13. The router of  claim 12 , wherein each route processor includes a Pre-IFIB, wherein a subset of entries in the IFIB are stored in each Pre-IFIB, and wherein the means for forwarding the reassembled packet to one of the plurality of route processors as a function of an internal forwarding information base (IFIB) includes means for accessing the Pre-IFIB. 
     
     
       14. A router, comprising:
 a plurality of route processors, including a first route processor; 
 means for receiving a plurality of packets; 
 means for detecting packet fragments among the plurality of packets; 
 routing the packet fragments to the route processor as a function of a packet fragment routing policy; 
 means for assembling the packet fragments into a reassembled packet; and 
 means for routing the reassembled packet to the first route processor of the plurality of route processors as a function of an Internal Forwarding Information Base (IFIB) that maps one or more flows to the plurality of route processors, 
 wherein the route processor includes a Pre-IFIB , wherein a subset of entries in the IFIB are stored in the Pre-IFIB, and wherein the means for routing the reassembled packet to a route processor as a function of the IFIB includes means for accessing the Pre-IFIB. 
 
     
     
       15. The router according to  claim 14 , wherein routing the packet fragments to one of the plurality of route processors as a function of a packet fragment routing policy includes means for generating an address as a hash of the source and destination addresses associated with the packet fragment.